An apparatus for coating motor-vehicle bodies wherein an arrangement of external electrodes carries a high-voltage potential is known to have substantial advantages when used with conductive spraying materials such as so-called water-enamels. Examples of such are shown in the prior art German OS 34 29 075 and 36 09 240. The external electrode arrangement is advantageous in overcoming insulating problems, since the entire paint-line system as far as the spraying head can be grounded The prior art external electrode arrangement teachings, however, have one major draw-back in that it is extremely difficult to prevent contamination of the spraying device, especially in the vicinity of the electrodes, the electrode-holding arrangement and the atomizer-housing, with the coating material Contamination of the electrode-area results in a drop in output, i.e. reduced efficiency and this, in turn, increases the tendency towards still heavier contamination by the sprayed material For this reason, the prior art apparatus disclosed in German OS 34 29 075 has only two, three or, at the most, four charging electrodes, each of which is embedded in a plastic holder extending radially from the external housing of the spraying head and axially towards the workpiece to be coated. The rear end of each of these electrode holders are secured to an annular element located upon the external housing of the spraying head and also made of plastic. In contradistinction, the apparatus described in the prior art German OS 36 09 240 comprises an annular element surrounding the external housing of the spraying head and made of an insulating material from which several needle-shaped electrodes, if necessary carried in finger-like extensions, project. An electrical conductor, connecting the circle of electrodes together, is connected to a high-voltage line and is insulated. This provides a spray-pattern which is more uniformly charged than when only three or four individual electrodes are used. Although these circular electrode designs have been found satisfactory in practice, they are found deficient in that they fail to overcome contamination about the electrode area. Experience has shown that a larger amount of sprayed paint-particles can be deposited upon the insulated surfaces of the electrodes, upon the spoke-like supports carrying the electrode-arrangement, and upon the atomizer housing, instead of being deposited upon the workpiece to be coated.